Elysium Blackwing Lair (Patch 1.6) has been released on July 19th along with a fix to the herb respawn rates.

In the dark recesses of the mountain's peak, Deathwing’s eldest son Nefarian, guiding some most awful experimentation, controlling mighty beings puppets and combining the eggs of different dragon flights with horrific results. In order to prove success, Nefarian even pursuits of rest on the horizon.

The Lord of Blackrock is not a mere scientist, but a great dragon cornered in his lair.